During his contribution to the showcase, Simpson performed "Red Headed Rounder," a song that, he explained to the audience, Haggard wrote with Nelson in mind, the title a nod to the latter's seminal 1975 album, Red Headed Stranger. The song was among the last recordings Haggard made before his death.

"Well, now, he sleeps all day, plays his cards all night / Smokes marijuana 'cause it treats him right," Simpson sang. "Well, that red headed rounder, he's a friend of mine / Well, that red headed rounder has a good time all the time."

The sentiment of the song echoed many of the evening's other performers in recognizing Nelson's humanity and commitment to his friendships, in addition to his substantial legacy as an icon in country music. For Simpson, performing a song written by Haggard also meant honoring a special connection he held with that legendary artist, as well. In a 2015 Billboard interview, Haggard named Simpson as one of the genre's most promising young talents, in his view.

"You hear a lot of Waylon [Jennings], a lot of George [Jones]," Haggard said of Simpson at the time. "He's got something going energy-wise that I haven't seen in a long time."

The tribute concert to Nelson was filmed for broadcast, and is set to air on the A&E network in 2019.